I wrote a simple program to test FFTW_DHT and compiled it both on Lin and Win. The input data is /1.0 2.0 3.0 4.0/.
The output on linux is:
10.0 -4.0 -2.0 0.0
The output on Windows is:
0.0 0.0 0.0 0.0
The output on Linux is the right answer. I don't know why I will get all zeros on Windows.